This invention relates to a process for making dispersable surfactant capped nanocrystals. More particularly, it relates to a process for making dispersable surfactant capped nanocrystals of metal oxides with non-hydroxylated particle surfaces using a non-hydrolytic single precursor approach, and to the nanocrystals made thereby. Still more particularly, it relates to a process for making dispersable surfactant capped nanocrystals of transition metal oxides.
The advent of new methods to prepare semiconductor and metal nanocrystals, specifically the injection of molecular precursors into hot organic surfactants, has yielded markedly improved samples with good size control, narrow size distributions, and good crystallinity of individual and dispersable nanocrystals (see references 1-3). It is of considerable interest to apply these methods to the synthesis of metal oxide nanocrystals, particularly transition metal oxide nanoparticles, which typically are prepared by methods involving water as solvent or reactant (4-9). Using nonhydrolytic preparations of metal oxide nanocrystals at high temperature in organic surfactants in the absence of air or water, one observes markedly different properties with respect to defect structure and surface composition. So far as applicants are aware, there has been only one example of the solution-based nonhydrolytic synthesis of individual TiO2 nanocrystals (10). Metal oxide nanocrystals with nonhydroxylated surfaces are believed to have significant advantages for applications in catalysis, ceramics, energy storage, magnetic data storage, sensors, ferrofluids, etc.
The following references contain useful background information pertaining to this invention , and are incorporated by reference herein in their entirety.
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